Eightincidents on May 7 and 8 included an "all-in brawl", four red cards for striking or punching, a coach verbally abusing an opposing player, another abusing a referee and a player who allegedly elbowed an opposition player, resulting in a broken jaw. The accused player was suspended for 12 weeks but would be appealing.
Some of the nine incidents on May 14 and 15 are still under investigation, others include a parent allegedly verbally abusing a referee, alleged verbal abuse from coaches to referees and a coach accused of physically abusing opposition players.
The union's referee manager, Cam Russell, said 14 red cards had already been issued this season and foul play or misconduct, on the field or from the sidelines, would not be tolerated.
He said the union had 13 reported referee abuse cases last year, the highest in the country.
"That is an embarrassing and unacceptable statistic."
Russell said the union was calling on the region's clubs and school teams to "clean up their game" and urging people who witnessed this behaviour to step in.
"We also need people witnessing any abuse at games to grab their cellphones and record it and report it to the union. Capturing video is the best evidence rather than just having to rely on verbal statements."
Former rugby union player and coach Errol Brain, who sits on the board of the Chiefs, said this was not the rugby anyone wanted to participate in or watch, and these incidents "reflect poorly on the game I dearly love".
"We need people involved in the game at all levels, including coaches, players and spectators, to act responsibly. This sort of behaviour is unacceptable.
"I can understand why the union's managers are so devastated. I feel sad and very disappointed when I read and hear reports of this nature."
Brain said he "applauded" the union for dealing with complaints quickly and sending a clear message about fair play expectations.
"If people are not prepared to change the way they behave at games, we don't need them involved in the sport."
Former Warrior and NZ Rugby League and NRL ambassador Henry Fa'afili, who is also the head coach and trainer at the Tauranga Boxing Academy, said these incidents were "totally unacceptable" and needed to stop.
"It's pretty sad for the game that incidents of this kind even happened at all. This is not what the game of rugby is all about.
"I know everybody is passionate about the game and their club, but I think people need to have a good hard think about what they're doing and become better role models.
"I think it's important before the situation gets any worse, that the rugby union organises a meeting with all coaching staff to reinforce that this behaviour won't be tolerated."
Te Tuinga Whanau Support Services executive director and stalwart Te Puna Rugby Club supporter Tommy Wilson said the abuse was "poor role-modelling".
He said referees did not deserve to be verbally or physically abused and physical or verbal violence on and off the sporting field was "unacceptable".
"This sort of behaviour undervalues the taonga of our referees.
"Unfortunately, these incidents are reflective of the types of behaviours we're seeing more and more in our community, particularly in the work we do."
'Referees are not robots, we're human'
A former union player and Bay of Plenty rugby referee, who asked not to be named, said these incidents were affecting some referees' mental health.
"I would like to say I'm shocked by the number and nature of these incidents, but I'm not.
"In my opinion, we're a society that doesn't deal with our emotions very well from a sporting perspective. We all have frustrations in life, but sometimes those emotions boil over onto match officials, including referees, who become targets for abuse," he said.
The referee said he had copped abuse, including from a player, who repeatedly challenged how he was officiating the game this year.
He recalled getting abused last year by two spectators, including a teenager, unhappy about the refereeing.
The referee said it was his practice to always shake the hands of players and coaches at the end of the game and sometimes the response he got was "thanks for nothing".
"I'm a robust-enough person not to take these comments or abuse personally, but you do think to yourself why did I waste two or three hours of my time to be treated like this."
He has also had to remove spectators from games for being abusive.
He said for some referees, it could be "quite intimidating and hurtful", being the subject of derogatory comments from players and/or spectators, such as being told, "you're ******* useless".
"It's the lasting effect on some referees who regularly cop abuse that's very concerning. It definitely has an impact on their mental health and enjoyment of the game.
"People need to understand referees are not robots, we're human like everyone else. We do make mistakes and errors in judgment from time to time.
"I think people forget that not all decisions are clear cut or obvious and we shouldn't be expected to put up with this sort of behaviour from anyone.
The referee said these sorts of incidents deterred people from participating in or refereeing the sport, and were being seen at every level across the country.
"Remember, referees and other match officials are volunteers and if they're not being treated with respect they could walk away from the game.
"My message to all clubs, including spectators, is that if we work together we can create a more positive environment and a better understanding and respect for each other."
Sports Bay of Plenty has joined 14 sports organisations nationwide in signing up for the Good Sports initiative launched by Sport New Zealand and Auckland-based Aktive Sports & Recreation.
The aim is to help raise adults' awareness about how their behaviour affects youth sport and to promote a positive shift in that behaviour.
Sports Bay of Plenty chief executive Heidi Lichtwark said foul play and sideline abuse had "absolutely no place in sport" and they applauded the union's quick response.
Lichtwark said players, spectators, coaches and parents all played a vital role in creating and sustaining sporting experiences that encouraged people to keep coming back.
"That's particularly important for young people who are more likely to follow the behaviours modelled by adults around them. A positive playing environment is critical to keeping young people engaged in sport.
"We encourage clubs and sporting codes to reach out to our sports development team if they would like to know more."